Don't be a bad quitter! Here's how to resign the right way.Shutterstock

Alison, 35, a beauty editor — who withheld her full name for professional reasons — was initially pleased when a 23-year-old reporter on her staff announced she’d gotten a new job.

“It was at a competing company, but that’s the way our industry works,” Alison says. “People jump to get ahead.”

But her happiness quickly turned to horror during the staffer’s final two weeks.

“She would go out for hours-long lunches and she would loudly talk on the phone to business contacts about how glad she was that she was getting out.”

Alison gritted her teeth until her staffer left — but hasn’t forgotten.

“Just a few weeks ago, someone asked me if I would recommend her [for a job]. Based on her behavior? No,” she says.

The lesson: How you leave your job can seriously impact your career.

According to Monster, Jan. 6 is the busiest day of the year to look for a new job — which means resignations are right around the corner. If you’re one of the lucky ones about to add a new line to your resume, here’s how to resign without aggravating your soon-to-be-past employer.

Tell your boss first

It’s tempting to tell your best work friend about your amazing new job offer, but the first person you need to tell is your manager, and it needs to be an in-person conversation, says Mikaela Kiner, founder of HR firm uniquelyHR. Realize that even though it’s good news for you, it’s creating a stressful situation for your boss, so don’t spring the news on him or her unexpectedly. Schedule a 15-minute conversation so they can process the information and talk through next steps.

Think like your boss

Until you pack up your desk, your loyalty is still with your old job. If you’re in the middle of an especially busy time in the office, see if you can give three or four weeks’ notice instead of just two. That way, you’re not leaving the team in the lurch. If you’re jumping to a competitive firm, it may be best to let your new boss speak with your current manager instead of being the middleman. “In many cases, these types of situations can be resolved amicably by involving both parties,” says Kiner.

Keep criticism to yourself

Your supervisor may push for more insight into why you’re jumping ship, but experts agree it’s best to be vague. “There’s no point in complaining about your current employer,” reminds Kiner. Instead, share what the new role offers that you don’t have currently: You get to lead a team, you’ll have more responsibility. Your boss will read between the lines without you overtly saying why you didn’t like the current gig.

Keep mum on social media

Resist the urge to update your LinkedIn or Instagram on your new office until it’s actually Day 1 of the new job. Sharing the news ASAP makes it seem like you’re less than committed to riding out the last few weeks at your present job, experts say.

Make an exit plan

“Train your replacement if possible,” says Erik Episcopo, career adviser at resume-building firm Resume Genius. Not possible? Make a memo of need-to-know info about your job and projects, and leave it with your manager.

Say thanks

Even if you are kissing the ground once you leave your job, still send your boss a note saying you’re grateful for the experience. Kiner says it’ll go a long way. “In our world, people change jobs and industries so many times throughout their lives. A former boss could become a client . . . or even a new manager,” she says. “Thinking long-term and being gracious is essential.”